Charge Air Cooler Fan Control
SYSTEM DESCRIPTION
Crankshaft position sensor (TDC)cEngine speed
ECM
cCharge air cooler fan relayCharge air temperature sensorcCharge air temperature
Ignition switch
cStart signal
The ECM controls the charge air cooler fan operation corresponding to the engine speed, the charge air tem-
perature and the start signal. The control system has 2-step control [ON/OFF]. The ECM does not directly drive
the charge air cooler fan. It controls the ON/OFF charge air cooler fan relay, which in turn controls the charge
air cooler fan.
When the charge air temperature is above 67ÉC (153ÉF) and engine speed is more than 1,600 rpm, the charge
air cooler fan operates.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
I/C FAN RLY+When charge air cooler fan is stopped. OFF
+When charge air cooler fan operates. ON
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
8 G/ORCharge air cooler fan
relayEngine is running.
Charge air cooler fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Charge air cooler fan is operating.0-1V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-178
